02079nas a2200229   4500008004100000022001400041245013900055210006900194260007300263300001200336490000800348520116000356653001901516653002001535653005001555653002501605653001801630653003601648100002001684700002101704856012401725       2014                        eng d  a0926-860X00aEffects of method of preparation on catalytic activity of Co-Zn double-metal cyanide catalysts for copolymerization of CO2 and epoxide0 aEffects of method of preparation on catalytic activity of CoZn d  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUL  a300-3080 v4823 a<p>Co-Zn double-metal cyanide (DMC) complexes are well-known catalysts for ring-opening polymerization of epoxides and co-polymerization of CO2 and epoxides. This work provides an insight on structure-activity relationship of DMC for poly(cyclohexene carbonate) synthesis. Seven samples of DMC were prepared by different methods and mode of reagent addition. Highly active catalyst could be synthesized even without using a co-complexing agent. CO2 adsorption studies revealed that higher the guest-host interaction higher would be the catalytic activity. High density and strength of Lewis acid sites, moderate crystallinity, low crystal symmetry (rhombohedral/monoclinic), Cl- ions and coordinated tert.-butanol (complexing agent) control the catalytic activity for polycarbonates. Chloride in the structure avoided induction period by increasing acidity of the catalyst and thereby, improving the guest-host interactions. Polycarbonates with CO2 incorporation as high as 86 mol%, average molecular weight of 20900 and polydispersity index of 1.8 were prepared at complete conversion of cyclohexene oxide. (C) 2014 Elsevier B.V. All rights reserved.</p>10aCarbon dioxide10aCO2 utilization10aCopolymerization of CO2 and cyclohexene oxide10aDouble-metal cyanide10aPolycarbonate10aStructure-activity relationship1 aSebastian, Joby1 aSrinivas, Darbha  uhttps://library.ncl.res.in/content/effects-method-preparation-catalytic-activity-co-zn-double-metal-cyanide-catalysts-001775nas a2200205   4500008004100000022001400041245013400055210006900189260007300258300001200331490000800343520094400351653002001295653004101315653002501356653001801381100002001399700002101419856012901440       2015                        eng d  a0926-860X00aFactors influencing catalytic activity of Co-Zn double-metal cyanide complexes for alternating polymerization of epoxides and CO20 aFactors influencing catalytic activity of CoZn doublemetal cyani  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcOCT  a163-1720 v5063 a<p>Co-Zn double-metal cyanides (DMCs) show good catalytic activity towards copolymerization of epoxides and CO2. A deep insight into the structural aspects of the catalysts that control their catalytic performance is addressed in this work. Method of preparation of DMC catalysts was found to have influence on their structure, which in turn dictated their catalytic activity. Complexing agent (t-BuOH) and density of strong acid sites of DMC catalysts were found critical factors responsible for their activity. Selectivity of DMC towards polycarbonates depends on the amount of alkali ion content in their composition. Induction period of the catalysts was governed by the strength of acid sites and by the presence of dispersed ZnCl2 in the composition. This study provides an understanding of the prime features of DMC catalysts that can be tuned for high productivity of polycarbonates. (C) 2015 Elsevier B.V. All rights reserved.</p>10aCO2 utilization10aCopolymerization of epoxides and CO210aDouble-metal cyanide10aPolycarbonate1 aSebastian, Joby1 aSrinivas, Darbha  uhttps://library.ncl.res.in/content/factors-influencing-catalytic-activity-co-zn-double-metal-cyanide-complexes-alternating-0